It is known to apply plasma excitation fields to a region of a vacuum chamber for plasma processing a workpiece. Typically, the plasma excitation fields are supplied to the region by the pair of top and bottom electrodes in the chamber or one electrode in the chamber and a coil, located outside the chamber. A process region is formed between the top electrode and the bottom electrode. The process region is coupled to a gas that the fields convert into the processing plasma. The workpiece is usually a semiconductor wafer, or dielectric plate and the plasma is involved in forming integrated circuit features on the workpiece. The plasma in the vacuum chamber typically dry etches the workpiece, but in some instances results in materials being deposited on the workpiece.
As the size of workpiece continues to increase and as the size of the process region continues to increase, there are increased requirements for precise control of various parameters of the plasma processing the workpiece.
It is in this context that various embodiments of the present disclosure arise.